1. Field of the Invention
This invention relates generally to operating microscopes, and more particularly, to operating microscopes used in microsurgery and other delicate operations.
2. Related Art
Operating microscopes, according to which a surgeon is provided an enlarged view of the field of the surgery, are generally known in the art. See, for example, U.S. Pat. No. 4,484,498 to Muller et al., which shows a binocular operating microscope according to which a number of different individuals can simultaneously view the field of surgery.
Optical operating microscope technology has generally been quiescent in recent years. This is in part due to the fact that inevitably during surgery a layer of blood obscures the object to be imaged. That is, the ultimate limitation on the surgeon's vision is the layer of blood overlying the tissues of interest. Blood obscures the tissues to a degree depending on the amount of suction employed, how fast the blood seeps into the operating field, and so forth. Some amount of blood flow into the operating field is inevitable. In the case of particularly delicate surgery, such as microsurgery on the eye, the nervous system, and the like, blood in the operating field significantly obscures the nervous and eye tissues, preventing the surgeon from seeing the condition to be corrected by surgery.
Conventional operating microscopes cannot render transparent the layer of blood which inevitably covers the tissues on which the surgery is to be performed so that the surgeon can be provided an image of the underlying object.
U.S. Pat. No. 3,748,471 to Ross shows a "False Color Radiant Energy Detection Method and Apparatus" in which visible and nonvisible radiation (that is, visible and, for example, infrared radiation) are simultaneously reflected from an object and are optically and electronically detected. The nonvisible reflected radiation is converted into a false-colored visible image which is superimposed over the ordinary visible image, to produce a composite false-colored image highlighting portions of the object having a high degree of reflectivity in the nonvisible spectrum. Ross teaches that this apparatus may be of use in determining the relative health of plant life. For example, healthy foliage reflects infrared radiation more completely than does unhealthy foliage. Ross does not teach any apparatus or method whereby an obscuring layer of material can be effectively removed from an image to reveal the underlying object.
U.S. Pat. No. 4,596,930 to Steil et al. shows a charge-coupled imaging device in which different groups of detectors which are sensitive to light energy at different wavelengths are arranged in a single array. However, Steil et al. does not teach any means in which a layer of an obscuring material, such as blood, can be effectively removed from a visible image, such as that of an operating field.